Facing-tool for dressing valve-seats, &amp;c.



T. B. WILLIAMS, F. A. DEXTER & F. L. SMITH.

FACING TOOL FOR DRESSING VALVE SEATS, 6L0.

APPLICATION FILED MAY 21. I9l6. ,515I Patented May22,1917.

2 SHEETS-SHEET I.

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T. B. WILLIAMS, F. A. DEXTER & F. L. SMITH.

FACING TOOL FOR DRESSING VALVE SEATS, Qc. APPLICATION FILED MAY '27. 1916.

Patented May 22, 1917.

2 SHEETS-SHEET 2.

UMTD STATES PATENT tlFTr lttlEo THOMAS B. WILLIAMS AND FRED A. DEXTER, 0F ORANGE, MASSACHUSETTS, AND FRANK I1. SMITH, OF CHICAGO, ILLINQIS, ASSIGNORS TO THE LEAVITT MACHINE COMPANY, OF ORANGE, MASSACHUSETTS, A. CORPORATION OF MASSACHUSETTS.

FACING-TOOL FOB DRESSING VALVE-SEATS, 8w.

Specification of Letters Patent.

Patented May 22, 1917.

Application filed May 27, 1916. Serial No. 100,220.

To all whom it may concern.

Be it known that we, THoMAs B. NIL- LIAM-S and FRED A. DEXTER, residents of Orange, in the county of Franklin and State of Massachusetts, and FRANK L. SM'ITH, a resident of Chicago, in the county of Cook and State of Illinois, citizens of the United States, have invented certain new and use ful Improvements in Facing-Tools for Dressing Valve-Seats, 810., of which the following is a specification.

This invention relates to a facing tool for dressing valve-seats, etc., and particularly to a tool adapted for recutting valve-seats, etc, that have become worn or pitted as a result of long use, this class of tools being of a type especially adapted for attachment to a valve-casing and refacing a valve-seat in a pipe-line, or other location, in situ.

The present invention relates to a tool of the general type illustrated in various prior applications ofv Thomas B. Williams and Frank L. Smith, disclosing facing-tools of this class in which the tool has two main parts, to wit, a cutter and a cutter-bar, and in which the general direction of the tool is transverse to the aXis of the cutter, the construction being such that the tool operates against or between two fixed resistance points or surfaces of the work to which the tool is attached. Tools of this specific type are shown in the applications of said W illiams and Smith, Serial Nos. 3897, 3898 and 3899, filed January 23, 1915.

In particular the present invention is an improvement upon that illustrated in a prior application of Stuard, Smith and Williams Serial No. 77631, filed February 11, 1916, in which is disclosed a tool of the general class specified but having a cutter-bar carrying means for attaching it to the valvecasing at points within said casing, and preferably in or close to the cutting zone, the cutter-bar itself being of such a construction as to constitute a substantially solid bar, most of the operated and operating parts of which are contained to a large extent within the boundaries of the bar proper and project but slightly therefrom,

thus assuring the strongest and most solid type of construction capable of doing the work of a cutter-bar in a tool of the general class mentioned. In addition said application discloses a simple means for ad justing the pivotal element of the cutterbar (which cooperates with a correspondmg element of the cutteryboth lengthwise and crosswise of the cutter-bar.

In the tool of the present application all of the features just described as embodied in said prior application of Stuard, Smith and lVilliams are preferably retained. In the tool of said application relatively movable elements were employed on the cutterbar for engaging the interior of the valvecasing and holding the cutter-bar to said casing. Specifically said application discloses a pair of holding elements on the cutter-bar, one fixed and the other movable, the movable element being adjustable lengthwise of the cutter-bar to different positions for proper cooperation with valverings of different diameters. In the tool of said application, after adjusting this movable element up or down on the cutterbar to the desired position, it is necessary to effect an independent centering of the pivotal element of the cutter-bar between said fixed and movable stops. To do this it is usually necessary to loosen said movable element slightly, remove the cutter-bar from the valve-casing, then by measurement or otherwise determined the exact position to which the pivotal element should be shifted lengthwise of the cutter-bar and then shift it to the position so determined, after which the cutter-bar is inserted in the valve-easing again and the movable element shif ed slightly back to its former position to clamp the cutter-bar to the valve-casing again. This mode of centering the pivotal element, it will be seen, is somewhat slow and requires the exercise of considerable care in measuring the distance between the holding faces of the two holding elements and in the subsequent division of said space and the corresponding adjustment of the pivotal element to a centered position with respect to said holding faces.

In said prior application of Stuard, Smith and Williams the fixed holding element ust referred to is intended to cooperate directly with the bottom wall of the valve-casing instead of with the valve-ring with which the movable holding element cooperates; and this also has been found to be a disadvantage.

The principal object of the present im provements is to provide means for positively centering the pivotal element of the cutter-bar between the relatively movable holding elements that engage the valve-casing without having to remove the cutter-bar from the casing and measure diameters and adjust, in the manner last described. In order to accomplish the desired result we prefer to associate the movable holding element for engaging the casing and the piv-* otal element to be centered relatively thereto in such a manner that when a movable ele ment is shifted to cooperate with a valvering of larger or smaller diameter the pivotal element will also be shifted; and the preferred construction is one in which such movable element and the pivotal element will move simultaneously but differentially, the movement here being at a two-to-one ratio in order that the centering movement of the pivotal element may always be 8X- actly one-half of that of said movable element.

A further object of the present improvements is to provide a cutter-bar in which the holding elements for engaging the valvecasing will all, whether fixed or movable, cooperate with the interior of the valve-ring to be refaced and will be wedged in place within said ring.

Other features of the present invention not hereinbefore referred to will be hereinafter described and claimed and are illustrated in the accompanying drawings, in which- Figure 1 is a sectional side elevation of a facing-tool embodying the present invention in operative relation with a pair of valveseats.

Fig. 2 is an end elevation of the tool shown in Fig. 1, looking from the left in said view.

Fig. 3 is an enlarged elevation of the cutter-bar and parts carried thereby, looking at the outer face of said bar, with the holding elements adjusted for a valve-ring of large diameter and the pivotal element centered between them.

Fig. 4 is an edge elevation of said cutterbar.

Fig. 5 is an elevation similar to Fig. 3, looking at the inner face of the cutter-bar.

Fig. 6 is an elevation similar to Fig. 3, but broken at the center and with an operating crank attached, illustrating the holding elements on the cutter-bar adjusted for a valve-ring of small diameter with the pivotal element centered between them.

Figs. 7 and 8 are enlarged details showing, in elevation and in horizontal section respectively, details of the operating devices for adjusting the positions of various parts on the cutter-bar.

Similar characters designate like parts in all the figures of the drawings.

As in the tools shown in the aforesaid applications the present tool is preferably one made up of two main parts connected by a pivotal or universal joint and disposed in a general direction transverse to the axis of the cutter-bar and adapted for operation while in engagement with a plurality of resistance points or surfaces located outside the tool, that is, lying in the work or its equivalent. This tool also has comparatively thin main members in order that it may work in small spaces. The cutter is preferably, as insaid applications, a rotary cutter operated by a ratchet-feed lever connected to the cutter in such a manner that this main element as a whole occupies as little space as possible in the direction of its thickness.

The other main element of the tool, viz., the cutter-bar, is also very compact and as in the aforesaid application of Stuard, Smith and WVilliams is so constructed that it has the important advantage of practically inclosing suitable operating means for efiecting the various necessary adjustments of the main parts mounted on the cutter-bar while retaining the appearance of, and functioning as, a solid and comparatively thin bar; and this substantially solid bar is preferably so made that it can be locked to the interior of a valve-casing in proper position for cooperating with an associated cutter-bar by bringing the holding elements on the bar into engagement with a suitable wall or walls inside the valve-casing, preferably the inner wall of a valve-ring.

The two main elements of our present tool may be of any suitable construction coming within the foregoing disclosure. They are shown as a ratchet-feed cutter of suitable type, such as A, and a cutter-bar, such as B. These two main elements have a pivotal connection, usually a face-to-face connection, as by means of a balland-socket joint, 23, for permitting ready connection and disconnection of such main elements by movement substantially in a straight line crosswise of the tool. This connection permits one main element to be inserted in the opening between a pair of valve-seats in a valve-casing in advance of the other and the second member afterward inserted and the complementary bearing elements then properly associated, as by merely inserting the ball part 2 in the socket 3, after these two elements have been located substantially in working position between a pair of opposed resistance surfaces, such as the valve-seats r and r, of the casing C. Such a universal connection as this of course permits relative tipping of the parts A and B, to enable the cutting edges to face surfaces at widely varying angles.

The element A shown comprises a lever, 1, a cutter proper, c, and a ratchet-feed conneetion between said lever and cutter for converting oscillating movement of the lever about the cutting axis into a step-by-step rotation of the cutter proper. This cutter 0 preferably has a multiplicity of cutting blades, or cutters proper, c, as in the afore said applications, the specific features of said ratchetfeed cutter being set forth more fully in a prior application filed by said Williams and Smith, January 23, 1915, Serial N0. 3900.

The main element B of this tool is shown as a substantially solid bar readily insertible down into the valve-casing, C, and adapted to form a support for the cutter. Usually the two main parts,Aand B,will engage directly, and work between, resistance points or surfaces such as those shown at r and 1",

though when these surfaces are spaced at a considerable distance apart auxiliary means carried by the cutter-bar may be employed for engaging the surface with which it coacts. As in the aforesaid application the relative separation of these two main parts Wedges them between the opposite resistance surfaces between which they work.

Suitable means must of course be employed for holding the two main elements A and B in proper working relation when the tool is in use. That employed in the present case is shown as of the same general type as the corresponding means illustrated in the tool of the aforesaid Stuard, Smith and Williams application. While the cutter-bar constitutes the principal means for locating the cutter in place, it is held against movement transversely of the cutting axis in engagement with a plurality of points in the interior of the valve-casing G. In the construction shown this result is brought about by providing elements on the cutter-bar having relative movement lengthwise thereof, as in the aforesaid Stuard, Smith and Williams application. In this case, however, said relatively movable elements, while they are wedged in place between two surfaces inside the casing, are not wedged between the bottom wall of the valve-casing and the upper wall of a valve-ring as in said appli cation, but are wedged between different points in the annular inner wall of the valvering. A suitable holding element, such as 5, movable lengthwise of the cutter-bar, is employed as in the aforesaid application, and with it cooperates, in the specific construction shown, a fixed holding element in the form of a projection, 7. Each of these holding elements 5 and 7 is so shaped as to present a convex working surface for engaging the corresponding concave inner wall of the valve ring. When these two parts are wedged between two opposite points in the inner wall of the valve-ring, as shown, it will be clear that the cutter-bar will be locked securely to said valve-ring and will also be locked in the direction of the cutting axis by contact of the outer face of the cutter-bar with the valveseat of said valve ring.

The part 5 is here shown as a projection from the cutter-bar having a round upper surface where it is intended to make contact with the valve-ring, this projection being carried by, and preferably integral with, a slide, such as S, movable on suitable ways lengthwise of the cutter-bar B. Said cutterbar is shown as an open-frame having siderails, 6, connected by upper and lower crossbars, 7 and 8, and said side-rails have ways on which the slide S is intended to move. By suitably adjusting the position of the slide S lengthwise of the cutter-bar it will be clear that the parts 5 and f may be spaced at any desired distance apart, within the limits of the tool, for wedging the cutter-bar in place or releasing it from the interior of the valve-casing. The means for moving the holding slide S lengthwise of the cutter-bar and thereby adjusting the position of the holding element 5 relative to the cooperating holding element f is preferably a feed-screw, such as 10, extending lengthwise of the cutter-bar and passing into, and in this case through, a longituidnal bore in the slide S, which bore is suitably threaded to correspond to the threads, 11, of the feed-screw. At its upper end this feed-screw is shown as held in place by a pair of stops, 12 and 13, secured to the smooth shank of the feedscrew and in engagement with the lower and upper sides of the cross-bar 7 before referred to and another cross-bar, 1a. This feed-screw 10 may be turned in any suitable manner as by means of a crank, 15.

For the purpose of adapting the cutterbar for use in valvecasings having valveseats spaced far apart, or of such a nature as to require auxiliary means for engaging a valve-seat, we may employ such auxiliary means, either at the movable or at the fixed holding point of the cutter-bar, or at both. Here we have shown a plurality of such auxiliary holding devices or stops, such as 16, in connection with the movable element, they being secured in this case to the slide S; and we have also shown a plurality of such auxiliary elements at the fixed holding point, this being indicated at 17. The stop members 16 operate in a manner similar to that in which the elements 17 operate, e11- gaging, however, the portion of the casing above the valve seat. It will be understood that when the valve seats are spaced a great distance apart, these elements 16 and 17 need only be extended to move the cutter bar 6 a suffieient distance from the adjacent valve seat to permit the operation of the cutter. Even when the cutter bar is so moved away from the valve seat, the members 5 and f will extend into the circle of the valve seat and engage the same. When the circle of the valve seat is referred to, it should be interpreted as meaning that portion of the valve seat which extends in angular relation to the face thereof.

The pivotal element carried by the cutterbar for operatively associating the cutter and the cutter-bar is intended, as in the tools of the applications before referred to, to have suitable adjustment, preferably both lengthwise and crosswise of said cutter-bar. Here the pivotal element 2 is located between the fixed and movable holding points f and 5 of the cutter-bar and is intended to be centered between them. In order to accomplish this result the pivot element 2 is here mounted on a centering slide, S, preferably carried on the same ways as the slide S so as to move in the same plane as said slide. Suitable means, preferably extending lengthwise of the cutter-bar and here shown as of the same general type as that employed for shifting the slide S, may be employed for effecting the desired movements of the slide S lengthwise of said bar. As before stated, this centering operation differs from that of the tool disclosed in the aforesaid Stuard, Smith and Williams application, in that the pivot element preferably moves simultaneously with the movable holding element and at such a ratio to the movement of said movable holding element as to be always maintained in a centered position between the holding elements of the cutterbar. In the construction illustrated the slide S is moved lengthwise of the cutter-bar by the same feed-screw 10 that operates the slide S. The screw-threads 11 of the upper part of this feed-screw 10 are of coarse pitch in this case, and the lower end of the feedscrew 10 has screw-threads, 18, of fine pitch, in order to effect the desired relative movements of the slides S and S. Here the ratio between the threads 18 and 11 is two-to-one, that is, the ratio is such that while both of the slides will move together, up or down the cutter-bar, the movement of the slide S will always be twice as great as that of the slide S, and hence the slide S will always be maintained with the pivotal element 2 in a centered position between the holding elements 5 and f. The mode of operation of the parts will be obvious from the drawings; and it will be equally obvious that the two slides S and S will always be maintained by the engaging screw-threads in any position to which they may be shifted. A very quick, and of course an exact, adjustment or centering of the pivot element 2 is obtained by the means just described or its equivalent.

Our present tool also preferably embodies means on the cutter-bar for shifting or adjusting said pivotal element in a direction crosswise of the cutter-bar and from a point outside of the valve-casing, preferably from the upper end of the cutter-bar, as in the case of the other adjustments previously de scribed. By providing such means the operator is enabled to adjust the pivot element 2 crosswise of the bar at the beginning of operations to obtain a working relation between the parts A and B and the surfaces with which they cooperate; and he is also enabled to feed the cutter up to the work as required by simply further operating said means for shifting the pivot element 2 crosswise of the cutter-bar. This last movement of said pivot element, will, of course, be in a direction toward the cutter and should follow up the cutter as the chips are removed from the surface with which the cutters 0 are in contact.

The means preferred in the present tool for effecting these movements or adj ustments of the pivot element on the cutter-bar in a direction crosswise thereof is similar to the operating means previously described for adjusting the slides S and S lengthwise of said cutter-bar. Here a feed device in the form of a long rod extending lengthwise of the cutter-bar is shown, at 19, as passing through cross-bars 7 and 1 1 and the slide S and into the centering slide S. This rod 19, as illustrated, constitutes a feed-screw of the type in which a worm, 20, is employed to turn a worm-gear, such as 21. The worm 20 is held between cross-bars, 22 and 23, of the slide S (as shown in Fig. 7). The shank of said pivot element is shown as threaded (see Fig. 8) through a correspondingly threaded bore in the worm-gear 21, the construction being such that when the worm-gear 21 is turned by the worm 20 of the feed-screw 19 the threaded shank of the pivot element, by engagement with the threads of the threaded bore of the worm-gear 21, will be moved crosswise of the cutter-bar, turning. of the pivot element relative to the slide S in which it is mounted being prevented by its being splined thereto, as indicated at 2a. The slide S is illustrated as of box-like construction, it having a plate, 25, screwed on the cross-pieces 22 and 23, for closing the upper side of said slide and maintaining the parts carried thereby in place.

Both of the feed-screws 10 and 19 are intended to be operated, as by cranks, from the upper end of the cutter-bar. The feedscrew 19 is illustrated as a two-part rod the lower element 19 of which is intended to turn in the upper element, 26, and also to have longitudinal movement to enable it to move up and down with the slide S. This result is here obtained by providing a long key-way, 27, in the rod 19 and splining it inside the tubular upper portion 26 of said rod, which upper portion has a pair of stops, 27 and 28, for preventing longitudinal movement thereof- While permitting free turning and as passing of the upper element 26. It will be clear from Fig. 3 that the lower part 19 of this feed device is freely movable in and through the upper tubular part 26 while the lower end of the rod though rotatable is always held against longitudinal movement relative to the slide S.

As will be evident from the foregoing, all of the operating parts of the main element 13 are centered, as far as possible, in the flatwise plane thereof, as in said Stuard, Smith and Williams application, so that the element as a whole is almost a solid bar with but few necessary projections from the walls thereof. The operating devices are suchthat all of the holding, centering and feed movements or adjustments are governed from the outside of the valve-casing and practically from a common point, to wit, the upper end of the cutter-bar B. In addition, the centering device always cooperates with the holding devices in such a manner as to divide exactly the space between the holding elements in all positions of the latter from maximum separation, as in Fig. 3, to minimum separation thereof, as in Fig. 6. The range of use of the tool is substantially the same as that of most of the tools of the applications before mentioned, and of course the tool is adapted for reversal to face the opposite valve-seat r, after one valve-seat, such as 1', has been faced.

What we claim is:

1. A tool of the class described, comprising a cutter and an associated cutter-bar having a pivotal connection, said cutterbar also having near the cutter a plurality of relatively movable elements for engaging a valve-casing and holding the cutterbar to said casing, and means carried by the cutter-bar to effect relative movement of said holding elements and also simultaneous movement of the pivotal element carried by the cutter-bar relative to said holding elements.

2. A tool of the class described, comprising a cutter and an associated cutter-bar having a pivotal connection, said cutter-bar also having near the cutter a plurality of relatively movable elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, and means carried by the cutter-bar to effect relative movement of said holding elements and also simultaneous movement of the pivotal ele ment carried by the cutter-bar relative to said holding elements.

3. A tool of the class described, comprising a cutter and an associated cutterbar, having a pivotal connection, said out ter-bar also having near the cutter a plurality of relatively movable holding elements for engaging a valve-casing and holding the cutter-bar to said casing, and means carried by the cutter-bar to effect a relative movement of said holding elements and to also simultaneously move the pivotal element carried by the cutter-bar relatively to said holding elements in all positions of the latter to center the pivotal element.

4. A tool of the class described, comprising a cutter and an associated cutter-bar having a pivotal connection, said cutter-bar also having near the cutter a plurality of relatively movable holding elements for engaging a valve-casing and holding the cutter-bar to said casing, and means carried by the cutter-bar and operable from a point outside the valve-casing to simultaneously efiect relative movement between said holding elements and relative movement of a predetermined ratio between the pivotal element carried by the cutter-bar and one of said holding elements in all positions of the latter.

5. A tool of the class described, comprising a cutter and an associated cutter-bar having a pivotal connection, said cutter-bar also having near the cutter a plurality of relatively movable holding elements for engaging a valve-casing and holding the cutter-bar to said casing, and means carried by the cutter-bar and operable from a point outside the valve-casing to simultaneously effect relative movement between said holding elements and relative movement at a two-to-one ratio between the pivotal element carried by the cutter-bar and one of said holding elements in all positions of the latter.

6. In a tool of the class described, a cutter-bar having at different points in the length thereof a pair of relatively movable holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of which parts is a fixed element and the other of which is carried by a slide movable lengthwise of said cutterbar, a pivotal element carried by said outter-bar for cooperation with a cutter, and means for imparting difi'erential feed movements to said slide and pivotal element lengthwise of the cutter-bar.

7. In a tool of the class described, a cutter-bar having a plurality of relatively movable holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, a pivotal element carried by said cutter-bar for cooperation with a cutter, and means for imparting differential feed movements to one of said holding elements and said pivotal element crosswise of the axis of the pivotal element from a point near the outer end of the cutter-bar.

8. In a tool of the class described, a cutterbar having at different points in the length thereof a pair of relatively movable holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of which parts is a fixed element and the other of which is carried by a slide movable lei'igthwise of said cutterbar, a second slide movable lengthwise of said cutter-bar, a pivotal element carried by said second slide for cooperation with a cutter, and means for imparting differential feed movements to said slides.

9. In a tool of the class described, a cutter-bar having at diiferent points in the length thereof a pair of relatively movable holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of which parts is a iixed element and the other of which is carried by a slide movable lengthwise of said out ter-bar, a second slide disposed between said holding elements and also movable lengthwise of said cuttcr-bar, a pivotal element carried by said second slice for cooperation with a cutter, and means for imparting dil 'ferential feed movements to said slides.

10. In a tool of the class described, a cutter-bar having a plurality oi holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of said holding elements being movable 011 said cutter-bar, a pivotal element carried by said cutter-bar and having its axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element.

11. In a tool of the class described, a cutter-bar having a plurality of holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-bar and having its axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element and at a two-to-one ratio.

12. In a tool of the class described, a cutter-bar having a plurality of holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-bar and having its axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element, said means including a common operating device.

13. In a tool of the class described, a cutter-bar having a plurality of holding elements for engaging the interior of avalvecasing and holding the cutter-bar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-bar and having its axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element, said means including a differential feed-device.

1a. In a tool of the class described, a cutter-bar having a plurality of holding elements for engaging the interior of a valvc-casing and holding the cutter-bar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-bar and having its axis crosswise thereof for cooperation with a cutter, and means for shift ing said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element, said means including a difierential feed-device having an operating device common to said holding and pivotal elements.

15. I11 atool of the class described,a cutter bar having a plurality of holding elements for engaging the interior of a valve-casing and holding the cutter-bar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-barand having its axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element, said means including a differential feed-screw.

16. In a tool of the class described, a cutter-bar having a plurality of holding elements for engaging the interior of a valve-casing and holding the cuttenbar to said casing, one of said holding elements being movable on said cutter-bar, a pivotal element carried by said cutter-bar and having is axis crosswise thereof for cooperation with a cutter, and means for shifting said movable holding element and the pivotal element relatively to each other transversely of the axis of said pivotal element, said means including a difllerential feed-screw having two sets of threads of two-to-one pitch, respectively.

17 A. tool of the class described, comprising a cutter and a cutter-bar having a pivotal connection, a plurality of relatively movable holding elements carried by the cutterbar for engaging a valve-casing and held ing the cutter-bar to said casing, and means carried by said cutter-bar for bringing about a proportional movement between the holding elements and the pivot element on he cutter-bar.

18. A tool of the class described, comprising a cutter and a cutter-bar having a pivotal connection, a plurality of relatively movable holding elements carried by the cutterbar for engaging a valve-casing and holding the cutter-bar to said casing, and means carried by said cutter-bar and including a single operating element for imparting relative movement to said holding elements and for centering the pivot element of the cutter-bar relatively thereto in all positions of said holding elements.

19. A tool of the class described, comprising a cutter and a cutter-bar having a pivotal connection, a holding slide on said cutter-bar and carrying an element for holding said cutter-bar to a valve-casing, a centering slide also movable lengthwise of said cutter-bar, and means carried by said cutter-bar for imparting to said slides proportional movements.

20. In a tool of the class described, a cutter bar, a plurality of holding elements movable with relation to each other lengthwise of the cutter bar and constructed and arranged to engage the interior of a valve ring, means on the cutter bar for effecting relative movement of said holding elements, and a cutter mounted on said cutter bar.

21. In a tool of the class described, a cutter-bar having fixed and movable holding elements constructed and arranged to engage the interior of a valve-ring, means on the cutter-bar for effecting relative movement of said holding elements, and a facing cutter mounted on the cutter bar.

22. In a tool of the class described, a cutterbar having a fixed and a movable holding element each in position and adapted for engaging the interior of a valve-ring and the latter movable lengthwise of said cutter-bar, means on the cutter-bar for shifting said movable holding element, and a facing cutter mounted on the cutter bar.

23. In a tool of the class described, a cutter-bar having a fixed and a movable holding element each in position and adapted for engaging the interior of a valve-ring and the former located near the lower end of the cutter-carrying end of the cutter-bar and the latter movable lengthwise of said cutter-bar, means on the cutter-bar near the opposite end thereof for shifting said movable holding element, and a facing cutter mounted on the cutter bar.

24. In a tool of the class described, a cutter bar having a plurality of holding elements relatively movable lengthwise of the cutter bar constructed and arranged to engage within the circle of the valve seat to position the same, and a cutter mounted on the cutter bar.

25. In a tool of the class described, a cut- Gopies of this patent may be obtained for five cents each, by addressing the ter bar having a plurality of relatively movable holding elements arranged to engage a valve casing, a cutter having pivotal connection with the cutter bar, and common means for effecting relative movement longitudinally of the cutter bar of the holding elements and movement of the cutter pivot.

26. In a tool of the class described, a cutter bar having a plurality of relatively movable holding elements arranged to engage a valve casing, a cutter having pivotal connection with the cutter bar, and common means for effecting the relative movement longitudinally of the cutter bar of said holding elements and the simultaneous movement of the cutter pivot to center the same.

27. In a tool of the class described, a cutter bar, a plurality of relatively movable holding elements, a cutter mounted on said cutter bar, a pivot between the cutter and cutter bar, and means for simultaneously effecting a diiferential movement between the holding elements and the pivot of the cutter.

28. In a tool of the class described, a cutter bar having a plurality of relatively movable holding elements, a cutter mounted on said cutter bar, a pivot between the cutter and cutter bar, and means for efiecting the relative movement of the holding elements and the simultaneous movement of the cutter pivot in a fixed ratio to the movement of the holding elements.

29. In a tool of the class described, the combination with a cutter bar having relatively movable holding elements thereon, of a cutter, a pivot extending between the cutter and cutter bar and movable on the latter, and means connecting the movable holding elements to the pivot in such manner that upon the movement of the former the latter will be moved a predetermined distance.

Signed at Orange in the county of Franklin and State of Massachusetts this 5th day of May A. D. 1916.

THOMAS E. WILLIAMS. FRED A. DEXTER.

FRANK L. SMITH. Witnesses:

NELLIE E. BLACK, NEWTON W. I-Iornnvs.

Commissioner of Patents,

Washington, D. G. 

